What should you know about reversible spirometry?

Spirometry measures how much air you breathe out and how quickly you do it. The test is performed before and after an inhaled bronchodilator. A noticeable change may support an asthma assessment, but the result must be interpreted with your symptoms, examination and medical history. It does not by itself confirm one diagnosis or exclude every other cause of cough or breathlessness.

Airflow can vary from day to day. Technique, recent medicines, smoking and an active respiratory infection may affect the test. A clinician may consider other explanations, including COPD, bronchiectasis or chronic cough, if the overall picture does not fit asthma.

Follow the testing service's instructions about inhalers, meals, smoking and strenuous activity. Wear comfortable clothing and tell the tester if you feel dizzy, wheezy or unwell. You may need repeated testing or another assessment when symptoms and the first result do not match.

Use prescribed Inhaler Therapy exactly as directed and ask for a technique check. If you smoke, a Smoking Cessation Programme can support stopping and reduce ongoing airway irritation. Keep a note of triggers, night symptoms, exercise limitation and reliever use for your review.

Contact a clinician promptly if breathlessness, wheeze or cough is worsening, waking you, or limiting ordinary activity. Seek emergency help for severe breathing difficulty, blue or grey lips, inability to speak in full sentences, confusion, collapse or rapidly worsening symptoms. Do not delay emergency care while waiting for spirometry.

Ask what changed between the two tests, whether the result fits your symptoms, which inhalers to pause before testing, and whether you need repeat spirometry or another lung assessment.